a143.设Sn是等差数列{an}的前n项和,若=,则s1S则=()a413A.2B1214C13D13144.已知偶函数f(x)满足f(x+4)=f(x),且在区间[0,2]上是增函数,则f(2019)>f(n)f(-4)的大小关系是())A.f(2019)